Grinding head



Oct. 22, 1957 D. PAPAGEORGES GRINDING HEAD 2 Shets-Sheet 1 Filed April 18, 19 56 D. PAPAGEORGES 2,810,241

GRINDING HEAD Oct. 22, 1957 ril 18, 1956 2 Sheets-Sheet 2 Filed Ap United States Patent GRINDING HEAD Demetre Papageorges, Liege, Belgium Application April 18, 1956, Serial-No. 578,9?8

Claims priority, application Belgium April 26, 1955 6 Claims. (Cl. 51-209 This invention relates to grinding heads fitted with hones or the like.

The main object of the invention is to provide an improved grinding head in which the hones are mounted parallel to the axis of rotation, projecting to opposite sides of the central plane of the head, so that when one end of each hone is Worn away its other end can be brought into operative position by reversing the head.

Another object of the invention is to provide an improved grinding head in which the hones are secured in place by means of an endless band shaped to contact with their outer faces and tensioned by means of clamping means located between the several hones.

A further object is to provide an improved grinding head in which the driving shaft is mounted upon an antivibratory support which enables the head to revolve at 1 high speeds without vibration.

A specific object of the invention is to provide an improved grinding head comprising a wheel or rotor with a plurality of flats upon its periphery, each of these flats being fitted with a hone of trapezoidal section projecting to opposite sides of the central plane of the wheel, with an endless band encircling the hones and holding them in place upon the flats, the wheel being reversibly mounted upon its driving shaft so that it can be turned over to bring the other ends of the hones into operation when their first ends are worn away.

Other objects, features and advantages of the invention will hereinafter appear from the following description of a preferred embodiment, given by way of example and with reference to the accompanying drawings, in which:

Fig. 1 is a plan of the grinding head with attached hones;

Fig. 2 is an elevation of the grinding head;

Fig. 3 is a sectional elevation of the head and of the support for the driving shaft; and

Fig. 4 is a plan in section on the line IVIV of Fig. 3.

In the drawings, numeral 1 represents a vertical driving shaft, upon the conical upper end of which there is fixed a plate 2 engaged by screws 3 for the attachment of a grinding head comprising a wheel or rotor 4 with arms 4a, the periphery of this wheel being formed with flats 5, for example eight in number. A like number of bones 6 are seated upon the flats 5 and held firmly in position by means of a collar or endless metallic belt 7, the projecting end faces 6a, 6b of the hones forming the operative grinding surfaces. Within the spaces 8 between the hones, the belt 7 is drawn inwardly by clamping plates 10 welded on the belt and engaged by screws 11 threaded into the periphery 12 of the wheel intermediate of the flats 5, the belt being thus undulated circumferentially so as to pull inwardly upon the hones as indicated at 811 in Fig. l, and outwardly upon the plates 10 and screws 11 as indicated at 8b. The function of the belt 7 is to constitute a rigid and easily adjustable assembly of the hones, which are subject to severe centrifugal force due to the high speed of the grinding head, but without introducing any ice crushing effects upon the outer corners and sloping sides of the hones.

The driving shaft 1 is mounted in a bearing support arranged to absorb vibration in the following manner.

The shaft passes through a bearing 13 preferably fitted with anti-friction balls 14, as shown in Fig. 3, mounted in a support 15 having a flange 16 at its upper end, which is shown as fitted with a locking ring 17 for the outer race of the ball bearing, another locking ring 17a being screwed upon the shaft 1 for locking the inner race of the ball bearing. Two spring rings 18 of angle-section are mounted around the bearing support 15, the cylindrical portions of these rings being surrounded by an adjustable liner 19 enclosed in a bore 200 of a frame 20. The flat annular faces of the upper ring 18 make contact respectively with the lower face 16a of the flange 16, and with the surface 20a of a frame recess housing the flange 16; the flat annular faces of the lower ring 18, parallel to those of the upper ring, make contact respectively with the lower face 20b of the frame 20, and with the face 25a of a bottom plate 25 which is held up towards the frame by bolts 21, the heads of these bolts being sunk in recesses in the flange 16 and their threaded ends 24 engaged in the bottom plate 25. The bolts 21 pass through perforations 23 in the frame 20, within which perforations they are surrounded by elastic sleeves 22.

The position of the liner 19 in the bore 200 of the frame is adjustable from the exterior by means of three screws 26 arranged radially at degrees apart in the frame 20, as shown in Fig. 4, so that it is possible to regulate the position and the inclination of the driving shaft 1 by turning these screws. It will be understood that the bolts 21 will have to be slackened when making such adjustment of the shaft position by means of the screws 26, and that when the desired adjustment has been obtained the bolts 21 will have to be tightened again in order to secure the benefit of the anti-vibration device.

One great advantage of the improved grinding head, as described above and illustrated in the drawings, is that it is symmetrical in relation to the axis X-Y, Figs. 2 and 3; thus, when the faces 6a of the hones are worn away, the head can be reversed, after removal of the screws 3, so as to bring the faces 6b into operation. After I both working faces have been worn away, up to near the edges of the belt 7, as viewed in Fig. 2, it will still be possible to push the hones endwise beneath the belt so that one end 611 or 6b will again project beyond the belt, the clamping screws 11 being slackened to allow this action.

The provision of long hones 6 affords a considerable reduction in the percentage waste of hone material due to the need to reject the hones when their length falls below a certain limit, this depending upon the peripheral speed of the wheel and the rigidity of the attachment of the hones, as well as their resistance to crushing.

Since the use of such grinding heads may give rise to vibration by reason of static and dynamic unbalance, and in order to avoid dynamic balancing of the wheel which would have to be modified as the hones wear, the invention provides the above-described anti-vibratory bearing support for the driving shaft, whereby high speed of operation may be maintained without ill effects.

Various modifications may be made to the described embodiment of the invention, within the scope of the appended claims, as the judgment of the manufacturer may dictate.

What I claim is:

1. A grinding head comprising a rotor having a plurality of flats upon its periphery, a plurality of hones seated upon the flats of said rotor, a band encircling said hones for holding them in place upon the flats, each of said hones projecting to opposite sides of said rotor and beyond said band, and means for clamping said band towards the center of said rotor at spaced intervals between said hones.

2. A grinding head comprising a wheel, a driving member, means for fixing said wheel reversibly to said driving member, the periphery of said wheel being formed with a plurality of spaced flats, a plurality of hones seated upon the flats of said wheel periphery, a band encircling said hones for holding them in place upon said flats, each of said hones projecting to opposite sides of said wheel and beyond said band, and means for clamping said band towards the center of said wheel at spaced intervals between said hones.

3. A grindinghead comprising a rotor having a plurality of flats upon its periphery, a plurality of homes seated upon the flats of said rotor periphery, and means for clamping said bones in place upon said flats,,in combination with a driving shaft forsaid rotor a bearing for said shaft, a support for said shaft bearing, a frame, a pair of angle-section elastic rings fitted around said bearing support, a plate surrounding said shaft, said rings having parallel annular flanges interposed respectively between said bearing support and said frame and between said bearing support; and said plate, and means for holding said plate towards said frame to press them tightly against the respective flanges of said rings.

4. A grinding head comprising a rotor having a plurality of flats upon its periphery, a plurality of bones seated upon the flats of said rotor periphery, and means for, clamping said homes in place upon said flats, in combination with a driving shaft for said rotor, a bearing for said shaft, a support for said shaft bearing, a frame, a

said liner, a pair of angle-section, rings fitted around said bearing support, a plate surrounding said shaft, said rings having parallel annular flanges interposed respectively between said bearing support and said frame and between said bearing support and said plate, and means for holding said plate towards said frame to press them tightly against the respective flanges of said rings.

5. A grinding head comprising a plurality of homes mounted upon a reversible wheel secured upon a driving shaft, characterized in that a plurality of homes of trapezoidal section are secured upon the periphery of the Wheel by means of an endless band presenting a succession of U-shaped hollows, the bones being located in hollows on the inner face ofthe band, and the hollows on, the outer face of the band being fitted with clamping plates held by screws engaged in the periphery of the wheel.

6. A grinding head according toclaim 5, characterized in that the driving shaft is mounted in an anti-vibratory support formed by a frame, a bearing, and a bearing support centered in the frame, elastic rings of angle-section being inserted between the bearing support and the frame, with the, annular flange of one of said rings gripped between the bearing support and the frame, parallel annular flange of the other ringbeing gripped between the bearing support and a backing member held towards said frame by bolts passing through said parallel annular flanges, andthe bolts passing also through perforations in the frame lined with elastic material.

References Cited in the file of this patent UNITED STATES PATENTS 2,307,632 Meyer Jan. 5, 1943 2,659,185 Indge Nov. 17, 1953 2,720,733 Ballash Oct. 18, 1955 FOREIGN PATENTS 674,387 Germany Apr. 13, 1939 

